Right. The good news is that people don't need to smoke anymore and they won't have to worry about the immorality of getting high, in order to feel relief from a health problem. Cannabis oil is now available which has no danger of losing your state of reason. So, really, there's even now LESS of an excuse to smoke.
Though I've heard the argument that one can smoke to get a buzz just like one can drink a few beers. It's a valid argument, in theory, though I can't say that with any experience.
Sure. I've known (personally) more people hooked on xanax (prescribed for anxiety) than on marijuana. It's far more addictive. In fact, it's often combined with alcohol. I sat next to a poor young lady on a flight (returning from a business trip), and she was clearly all strung out. She admitted to me later that she was on the flight to go to a rehab center in my area and that she had gotten hooked on xanax and alcohol. In addition, a co-worker of mine had his teenage daughter hooked on the same combo ... and she had to go to rehab. But people don't think twice about the morality of popping a xanax (which can also mess with your head too) if it's prescribed by a doctor. It's as if big pharma is also in charge of tuning our moral compass.
I don't see any morally relevant difference between drinking alcohol just to get a buzz and smoking enough pot just to get a buzz. Now, those could be venial sins without sufficient reason, e.g. doing it a lot just for entertainment (as Jone cited) ... as long as you don't lose your rational faculties. But if you have anxiety and stress, and either a glass or two of wine (or some part of a joint that gets you to the same place), I don't see any difference between the two. PS -- I've never tried marijuana.